title: Determination of prednisolone in human adipose tissue incubation medium using LC-MS/MS to support the measurement of 11beta-hydroxysteroid dehydrogenase activity.
abstract: A method for the determination of prednisolone in human adipose tissue incubation medium has been developed, validated and used to support studies designed to measure the activity of 11beta-hydroxysteroid dehydrogenase in human adipose tissue. After incubation, samples (80 microL) were extracted using Oasis HLB microElute SPE plates and the resulting extracts were analyzed using reversed-phase chromatography coupled to an Applied Biosystems Sciex PE API-4000 mass spectrometer with a TurboIonSpray interface (400 degrees C). The method was validated over the calibration range of 0.5-100 ng/mL. Intraday precision and accuracy were 6.1% R.S.D. or less and within 6.3%, respectively. Interday precision and accuracy were 4.2% R.S.D. or less and within 3.6%, respectively. Extraction recovery of prednisolone was greater than 84% over the range of low to high quality control sample concentrations. The validated assay was used to support studies designed to estimate ex vivo 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) enzyme activity in human adipose tissue.
authors.affiliation: Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., Thousand Oaks, CA 91320, USA.
authors.forename: X
authors.initials: X
authors.lastname: Ding
authors.forename: M J
authors.initials: MJ
authors.lastname: Rose
authors.forename: I
authors.initials: I
authors.lastname: McCaffery
authors.forename: J
authors.initials: J
authors.lastname: Rossi
authors.forename: K
authors.initials: K
authors.lastname: Paweletz
authors.forename: C
authors.initials: C
authors.lastname: Hale
authors.forename: M
authors.initials: M
authors.lastname: Emery
authors.forename: C A
authors.initials: CA
authors.lastname: James
mesh_terms: D042842:11-beta-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000273:Adipose Tissue / Q000737:chemistry* / Q000201:enzymology; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D003470:Culture Media; D006801:Humans; D011239:Prednisolone / Q000032:analysis*; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D003470:Culture Media; D011239:Prednisolone; D042842:11-beta-Hydroxysteroid Dehydrogenases